1. Field of the Invention
The present invention relates to an external apparatus for monitoring a communication system, and, more particularly to an external apparatus for monitoring a communication system for confirming a normal operation of a signaling processor for performing a communication process instead of a calling process.
2. Description of the Related Art
Various monitoring methods have been proposed for monitoring whether a communication software of a conventional exchange system is operating normally.
FIG. 1 (PRIOR ART) shows an example of a monitoring apparatus for monitoring the operation of a communication software of a conventional exchange system.
In FIG. 1, 1 designates an exchange network (called NW hereinafter), and exchange network NW 1 is connected to a calling processor (called CPR hereinafter) 2 subjected to an external monitoring.
3 designates an external monitoring apparatus comprising quasi-incoming trunks (called QICTs hereinafter) 4 and quasi-outputgoing trunks (called QOGTs hereinafter) 5.
Now, the operation of the above structure is explained. The external monitoring apparatus instructs the QICT 4 to start its examination in units of the predetermined intervals, in order to detect any abnormality. When the QICT 4 in the ESE 3 sends a quasi-call to NW 1 in accordance with the above instruction, the CPR 2 detects the quasi-call and enables the QOGT 5 in the ESE 3 to receive it. The monitoring of the CPR 2 is performed by repeating the quasi-outgoing call and the quasi-incoming call a discretional number of times, for example, two or three times sequentially at the predetermined intervals.
The NW 1 processes the quasi-call in the same way as an ordinary call. Namely, when the NW 1 processes the quasi-outgoing call normally and terminates the quasi-call at the destination trunk, the NW 1 is judged to be operating normally. However, if the NW 1 cannot terminate the outgoing call at the destination trunk, it is judged as operating abnormally.
If an abnormality is detected by this monitoring, the ESE 3 deems that the operation of the software system of the CPR 2 is abnormal. Then, an emergency action signal (called an EMA hereinafter) 6 is transmitted from the ESE 3 to the CPR 2 and the software system of the CPR 2 is initialized based on the EMA 6, and is thereby restored to its normal operation state.
FIG. 2 (PRIOR ART) shows another example of an apparatus for monitoring the CPR 2, using a conventional ESE. Each of a plurality of NWs 1 has a corresponding ESEs 3 and a plurality of CPRs 2 are connected to respective NWs 1. The CPRs 2 are connected to a main processor (called an MPR hereinafter) 7 for managing the communication process.
In the above recited multiprocessor system, when all the CPRs 2 simultaneously become abnormal, the MPR 7 is judged to be operating abnormally based on the monitoring of respective ESEs 3. Then, the software system of the MPR 7 is initialized, thereby enabling the monitor to determine whether or not the incoming call from an external apparatus is normal.
Various signaling methods are provided for use in telephone networks. No. 1 to No. 7 and R1 and R2 signaling methods are known as standard signaling methods recommended by CCITT (international telephone telegram consulting committee) in international lines. No. 6 and No. 7 signaling methods utilize a new data transmission technology and a common channel signaling method (called CCS hereinafter) in which various control signals are transmitted by a transmission line different from a message communication line.
No. 7 signaling system can not only be used in telephone systems but can also be expanded for use in ISDNs (Integrated Service Digital Networks). It has a data transmission rate of 64 k bit per second (digital signals) and 4.8 k bit per second (analog signals). Signal units used by the No. 7 signaling system do not have fixed lengths and have a larger line identification capacity than the No. 6 signaling system. Therefore, the No. 7 signaling system has been widely adopted.
The actual format of the above described CCS includes a corresponding network structure and a non-corresponding network structure. The corresponding network structure corresponds to the message communication lines among the exchanges on a one-by-one basis. The non-corresponding network structure forms a communication network independent of the message communication line and provides a signal transfer point (STP), thereby including an exchange as a communication terminal.
An intelligent network is provided for providing a high-quality telephone service. It comprises a service switching point (SSP) for performing an actual connection process and a service control point (SCP) for controlling the SSP. The SCP does not perform the connection processing, but stores the data necessary for the services in the data base and provides the necessary information in accordance with the request sent from the SSP by using the No. 7 signaling system.
The signaling processor (called SPR hereinafter) utilized in the above STP and SCP does not perform an ordinary calling processing. Therefore, it cannot confirm the normality of the software for a communication receipt by using the calling processing function of the external monitor of ESE3, as explained with reference to FIGS. 1 and 2.
To clarify this problem, the STP in the CCS system is explained by referring to FIG. 3. The network NW 1 shown in FIG. 3 is exclusive of the signal processing and is different from the NW 1 shown in FIGS. 1 and 2. In FIG. 3, it is connected to data transmission apparatus (DT) 13 through the No. 7 link.
A plurality of networks 1a . . . are connected to SPR 8 . . . and SPR 8a . . . , which perform a signal processing for a destination signal and do not perform a calling processing through the common channel signaling equipment (called CSE hereinafter) 9 and CSE interface (called CSEI hereinafter) 10.
The above recited SPR 8 and 8a are connected to a plurality of nodes (NODE) 11 which are connected to a local area network (called LAN hereinafter) and the node 11a is connected to the MPR 7. The MPR 7 is connected to the alarm shelf (called ALMSH hereinafter) 14.
In the STP with the above recited structure, the No. 7 signaling is supplied to the network 1a through the DT 13 and its destination is decoded in the CSEI 10 and the CSE 9. Then, it is transmitted to node 11a through the SPR 8, the respective node 11 . . . and the LAN 12 and further transmitted to the MPR 7. Thereafter, it is returned to the originating network 1a.
In the above recited STP, respective SPRs 8 . . . only perform a signal processing according to the No. 7 signaling system and do not perform a calling processing like the CPR 2 shown in FIGS. 1 and 2. Therefore, the external apparatus cannot monitor the call by using the ESE 3.
Further, as shown in FIG. 3, the SPR designated by 8a among a plurality of SPRs 8, is not directly connected to the network 1a and therefore the ESE 3 cannot be physically connected thereto.